To effectively use sewer system resources, reducing phosphorus content in incinerator ash was carried out in order to improve the quality of the ash when used as raw material for cement. The phosphorus removed from the ash is recovered as calcium phosphate. From the result measured the constituent of incinerator ash before and after the alkali elution, it was proved that phosphorus is eluted by 46% in an alkali solution. Although the mass of the ash after the elution decreased 14%, this was proved to be attributed to that phosphorus and aluminum can be selectively eluted to the solution. The phosphorus compound recovered as calcium phosphate contains phosphorus by 12%, and is 100% citric-acid soluble. With respect to toxic heavy metals specified by the Fertilizer Control Law, the contents of Cd and As were within the specifications, while Ni, Cr, Pb and Hg were not detected using the available chemical analyses. When the phosphorus compound was used as fertilizer, it was confirmed that the recovered compound is harmless to plant matter and there was no accumulation of heavy metals in crops. The contents of Mn and Zn were lower than crops grown using marketed fertilizer (superphosphate of lime and fused phosphate). Using an eggplants, the same effect as fertilizer was acquired with a quantity of recovered compound equal to half the amount of superphosphate of lime and fused phosphate. It was confirmed that the number of crops and crop yields can be increased by using a greater quantity of the recovered compound.

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The aim of this study is to evaluate H₂S desulfidation reactivity of calcined dolomite. Six dolomites having different CaO/MgO mole ratio were calcined at 1173 K under air atmosphere, and H₂S desulfidation reactivities of them were investigated by a fixed bed reactor.
H2S desulfidation experiments were conducted for 120 minutes at 1173 K under H₂S/N₂ atmosphere. In order to investigate effects of physical and chemical characteristics of calcined dolomites or calcined limestones on its conversions, EDX observation, SEM observation, MgO content in dolomite, BET specific surface area and pore volume were analyzed.
Consequently, it was found that conversions at 120 minutes are closely correlated with the BET specific surface area, and that magnesium oxide content in calcined dolomite have an important role for H₂S desulfidation.
The average H25 absorption capacity per weight of calcined dolomite was 1.17 times of calcined limestone.

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This study was made to investigate the characterization and HC1 gas removal of calcined dolomite hydrate (mixture of Mg (OH) ₂ and Ca (OH) ₂) synthesized by hydrating the calcined dolomite with water contained fructose. The calcined dolomite hydrate with ultrafine particles was synthesized by adding fructose solution to the calcined dolomite which was heated the dolomite at 1000°C for 1 hour. The sample was characterized by means of X-ray diffraction, measurements of specific surface area and particle size distribution.
The limestone, which was contained in the dolomite, was dissolved using 0.10 mol dm^-3 HC1 solution. The calcined dolomite was obtained by heating the treated dolomite at 1000°C for 1 hour. The calcined dolomite hydrate with ultrafine particle was synthesized by hydrating the calcined dolomite using fructose solution for 6 h, and was a mixture of Ca (OH) ₂ and Mg (OH) ₂. The specific surface area of the calcined dolomite hydrate increased with the increase of fructose/calcined dolomite mass ratio. In fructose/calcined dolomite mass ratio of 0.07, the specific surface area of the calcined dolomite hydrate was 147 m²·g^-1 Ca (OH) ₂ and Mg (OH) ₂ were uniformly dispersed in sample. The HC1 gas removal ability of the calcined dolomite hydrate was enhanced with increase of specific surface area.

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Calcium phosphate paste (CPP; major crystalline phases, α-Ca₃ (PO₄) ₂ and Ca₄ (PO₄) ₂0) was mixed with 1.0, 2.0 and 9.1 mass% of collagen type I solution (Col (I) -S); the mixtures were lyophilized at-7°C for 24 h and then ground. The resulting powders were kneaded with fresh blood and mixing liquid to form hardened bodies. These hardened bodies were immersed into the simulated body fluid (SBF) at 37.0 ± 0.2°C for desired periods. The amount of the mixing liquid that could be added to the CPP powder with Col (I) -S addition was examined without the addition of blood. The reciprocal ratio of powder to liquid, i.e., (P/L) ^-1, increased to 0.77; this value was approximately 38% higher than the case of CPP powder with Col (I) granules (Col (I) -G) with sizes below 150 pm. The immersion of CPP specimen with 9.1 mass% of Col (I) -S and blood addition (P/L ratio : 1.7) into the SBF for 7 d revealed that the changes of calcium phosphates in the CPP to hydroxyapatite (Ca¹⁰ (PO₄) ₆ (OH) ₂) were slightly retarded. The total porosity and compressive strength of this specimen were 66.5 ± 1.5% and 4.28 ± 0.04 MPa, respectively. The SEM investigation revealed that the grains were coated with collagen and appreciable difference in microstructure was observed. compared to the case of CPP specimen with Col (I) -G addition.

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